How can i make an object move to my aiming position?

Hi! I'm trying to learn about instantiate, and different types of forces, so i'm trying to make a cannon shoot a cannon ball, i've come to this.. It shoots the cannon ball, but i would want that the shot doesnt move always towards x axis, but instead, to move were the cannon is aiming, i leave my code and a picture that could help you guys, i'll apreciate your help :)

 using UnityEngine;
 using System.Collections;
 
 public class Disparar : MonoBehaviour {
 
     public GameObject cannonBall;
     public Transform spawn;
     public float thrust;
     public float gravity;
 
     void Start () {
         
     }
     void Update()
     {
         if (Input.GetButtonDown("Fire1"))
         {
             
             GameObject clone;
             clone = (GameObject)Instantiate(cannonBall, spawn.position, Quaternion.Euler(0f, 90f, 0f));
             clone.GetComponent<Rigidbody>().AddForce(thrust, gravity, 0f, ForceMode.Impulse);
         }
     }
     
     
 }